/Engine/Source/Runtime/MovieScene/Public/Channels/MovieSceneChannelData.h
Set the value of the key at InTime to InValue, adding a new key if necessary
The handle of the key
[FKeyHandle](API\Runtime\Engine\Curves\FKeyHandle) UpdateOrAddKey ( [FFrameNumber](API\Runtime\Core\Misc\FFrameNumber) InTime, [ParamType](API\Runtime\MovieScene\Channels\TMovieSceneChannelData\ParamType) InValue )